WAEC SSCE - Physics - 2019 (Objective)

Which of the following statements about a neutral atom is correct? The

An a.c. the generator can be converted to a d.c. generator by replacing the

A small amount of air is introduced into the vacuum above the mercury in a mercury barometer tube. The mercury level goes down because the air molecules

A device consumes 100 W of power when connected to a 120 V source. Calculate its resistance. 
 

In the diagram above, the time taken to trace a wave between P and Q is

If the efficiency of a transformer is 100%, which of the following equations would be correct? 
 

An 800 kg car moving at 80 km hr\(^{-1}\) collides with a 1200 kg car moving at 40 km hr\(^{-1}\) in the same direction. If the cars stick together, calculate their common velocity.

The nucleon and proton numbers of a neutral atom of an element are 238 and 92 respectively. Determine the number of neutrons in the atom. 

Which of the following statements is the correct reason for using soft iron in making the armature or an electric bell?

A transverse pulse of frequency 9 Hz traves 4.5m in 0.6 s. Calculate the wavelength of the pulse.

Which of the following devices is used for storing electric charges?

Which of the following liquids has the highest surface tension?
 

The vacuum in a thermoflask reduces heat loss resulting from

In which of the following media is the speed of sound the least?

An electron of mass 9.1 x 10\(^{-31}\) kg moves with a speed of 2.0 x 10\(^6\) ms\(^{-1}\) round the nucleus of an atom in a Circular path of radius

6.1 x 10\(^{11}\) m. Calculate the centripetal force acting on the electron.
 

Calculate the quantity of heat needed to change the temperature of 60g of ice at 0 °C to 80 °C. [specific latent heat of fusion of ice= 3.36 x 10\(^5\) Jkg\(^{-1}\) specific heat capacity of water 4.2 x 10\(^3\) J kg\(^{-1}\) K\(^{-1}\)]

The graph above illustrates the variation of temperature \(\theta\) with time (t) for a solid that is being heated. Which processes take place at segments P and Q respectively?

Which property of a wave remains constant when the wave travels from one medium into another?
 

When ultraviolet light is incident on certain metallic p articles are emitted. These particles are called

Which of the following cases cannot produce total internal reflection? A light ray travelling from

Which of the following thermometers is used to measure the temperature of the human body?

A freshly demagnetized bar magnet is placed in the East-West direction to ensure that

The diagram above represents an experimental set-up for verifying?

Which of the following graphs gives the correct relationship between energy and mass when mass is converted to energy.

Two bodies of masses 3.0 kg and 2.0 kg are separated by a distance of 50 cm. Calculate the force of attraction between them. [G = 6.67 x 10\(^{-11}\) Nm\(^2\) kg\(^2\)]

A body of mass 2 kg is released from a point 100 m above the ground. Calculate its kinetic energy 80m  from the point of release.

Which of the following characteristics of waves can a ripple tank be used to demonstrate?
I. Reflection
II. Refraction
III. Diffraction
 

A loaded spring is set in simple harmonic motion. The force that tends to restore the load to its equilibrium position is

Which of the following instruments can be used to compare the magnitudes of charges on two given bodies?

Which of the following materials does not serve as a safety device in electrical circuits? 
 

The time rate of increase in velocity is called

The diagram above illustrates a meter bridge circuit under balanced condition. Determine the value of x.

The wire of a platinum resistance thermometer has d resistance of 3.5\(\Omega\) at 0 °C and 10.52\(\Omega\) at 100°C. Calculate the temperature of the wire when its resistance is 7.5\(\Omega\).

An instrument used to measure relative humidity is the?

The anomalous expansion of water occurs in the range 
 

The induced current in a coil always flows in a direction so as to oppose the change that causes it. This statement is known as

Which of the following quantities is a vector?

Which of the following statements about a moving object is correct?

An electron of mass 9.1 x 10\(^{-31}\) kg moves with a speed of 2.0 x 10\(^6\) ms\(^{-1}\) round the nucleus of an atom in a Circular path of radius 6.1 x 10(^{11}\) m. Determine the angular speed of the electron.

 Which of the following graphs of a charge Q against potential difference V across the capacitor is correct?

Which of the following waves is not mechanical?
 

The mass of a load is doubled while the force acting on it is halved. The resulting acceleration of the load is

A rectangular piece of iron measuring 4 cm by 3 cm at 20\(^o\)C is heated until its temperature increases by 100 C. Calculate the new area of the metal. [Linear expansivity of iron is 1.2x 10\(^{-5}\) K\(^{-1}\)]

Which of the following properties is not exhibited by sound waves?

In an elastic collision, momentum is conserved as well as well as?

A ray of light traveling from a rectangular glass block of refractive index 1.5 into air strikes the block at an angle of incidence of 30. Calculate its angle of refraction.

The maximum and minimum thermometer reads the

The area under a velocity-time graph represents

The diagram above illustrates an object moving in a circular path at a constant speed. Which of the arrows indicates the direction of linear velocity?